linux-kernel - Re: [PATCH RFC 5/6] md/raid1: Handle bio

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <c03de5c7-20b8-3973-a843-fc010f121631@huaweicloud.com>
Date: Mon, 23 Sep 2024 14:15:33 +0800
From: Yu Kuai <yukuai1@...weicloud.com>
To: John Garry <john.g.garry@...cle.com>, Yu Kuai <yukuai1@...weicloud.com>,
 axboe@...nel.dk, hch@....de
Cc: linux-block@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-raid@...r.kernel.org, martin.petersen@...cle.com,
 "yangerkun@...wei.com" <yangerkun@...wei.com>,
 "yukuai (C)" <yukuai3@...wei.com>
Subject: Re: [PATCH RFC 5/6] md/raid1: Handle bio_split() errors



在 2024/09/20 18:04, John Garry 写道:
> On 20/09/2024 07:58, Yu Kuai wrote:
>> Hi,
>>
>> 在 2024/09/19 17:23, John Garry 写道:
>>> Add proper bio_split() error handling. For any error, call
>>> raid_end_bio_io() and return;
>>>
>>> Signed-off-by: John Garry <john.g.garry@...cle.com>
>>> ---
>>>   drivers/md/raid1.c | 8 ++++++++
>>>   1 file changed, 8 insertions(+)
>>>
>>> diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
>>> index 6c9d24203f39..c561e2d185e2 100644
>>> --- a/drivers/md/raid1.c
>>> +++ b/drivers/md/raid1.c
>>> @@ -1383,6 +1383,10 @@ static void raid1_read_request(struct mddev 
>>> *mddev, struct bio *bio,
>>>       if (max_sectors < bio_sectors(bio)) {
>>>           struct bio *split = bio_split(bio, max_sectors,
>>>                             gfp, &conf->bio_split);
>>> +        if (IS_ERR(split)) {
>>> +            raid_end_bio_io(r1_bio);
>>> +            return;
>>> +        }
>>
>> This way, BLK_STS_IOERR will always be returned, perhaps what you want
>> is to return the error code from bio_split()?
> 
> Yeah, I would like to return that error code, so maybe I can encode it 
> in the master_bio directly or pass as an arg to raid_end_bio_io().

That's fine, however, I think the change can introduce problems in some
corner cases, for example there is a rdev with badblocks and a slow rdev
with full copy. Currently raid1_read_request() will split this bio to
read some from fast rdev, and read the badblocks region from slow rdev.

We need a new branch in read_balance() to choose a rdev with full copy.

Thanks,
Kuai

> 
> Thanks,
> John
> 
> .
>